In general, a refrigerator is an apparatus for storing various types of items, e.g., food, at low temperature. Low temperature in the refrigerator is achieved by circulating cold air that can be continuously generated through a heat exchange process by using a refrigerant. During operation, the refrigerant goes through repetitive cycles of compression, condensation, expansion and evaporation.
During cold air circulation, the cold air that has flown through the interior of the refrigerator can return to the space where an evaporator is installed and is subject to heat exchange with the evaporator again. Then, the cold air can be supplied to other places of the refrigerator again.
However, cold air that has returned to a cold air generation compartment (hereinafter, referred to as “returned cold air”) likely contains a large amount of moisture. The moisture can adhere to the evaporator. Due to heat exchange between the returned cold air and the evaporator, moisture adherent to the evaporator tends to freeze and become unwanted frost.
Frost on the evaporator can compromise heat exchange efficiency of the evaporator. As a result, defrosting time of the refrigerator needs to be increased, thereby leading to increased power consumption of the refrigerator.
Patent Document: Korean Patent Application No. 10-2009-0006612 (filed on Jan. 15, 2009)